人體頭上長有數以萬計的頭髮,自皮膚下的毛囊生長出來。頭髮的生長週期可分為三個階段,在任何時間,我們的頭上均有處於不同生長階段的頭髮。

頭髮從毛囊基部長出並不斷生長,直至見於皮膚表面,方為完全成長,這階段為期2至6年6

頭髮停止生長,髮根開始萎縮。毛囊基部分解,頭髮向上移位,遠離毛囊根部及供應養份的血管。這個階段會維持幾個星期6

成熟的頭髮鬆脫地依附在髮根,通常於數月後脫落,或被新長出來的頭髮擠出6

參考資料:
1. Hong Kong Product Circular(Finasteride,MSD)
2. Data On File. MSD_Hong Kong
3. Kaufman KD, Olsen EA. Whiting D et al and the Finasteride Male Pattern Hair Loss Study Group. Finasteride in the treatment of men with androgenetic alopecia. J Am Acad Dermatol 1998;39: 578-589
4. Norwood. Male Pattern Baldness: Classification and Incidence southern Medical Journal 1975;Vol 68/No 11: 1359-1365
5. Rhodes t, Girman CJ, Savin RC. Dermatol Surg. Dermatol Surg. 1998;1: 1330-332
6. Dow stough. Psychological Effect, Pathophysiology, and Management of Androgenetic Alopecia in Men Mayo Clin proc 2005;80 (10): 1316-1322
7. Whiting DA and Howsden FL. Color Atlas of Differential Diagnosis of Hair loss Canfield Publishing 1998